Improvement in hot-air engines



PATENT OFFICEO OYRUS W. BALDWIN, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN HOT-AIR ENGINES.

Specification forming part of Letters Patent No. 55,601, dated June 19,1866.

To all whom it may concern.'

Be it known that I, GYRUs W. BALDWIN, of Boston, in the county ofSuffolk and State of Massachusetts, have invented a new and usefulImprovement in Heated-Air Engines; and l do hereby declare the followingto be a full, clear, and exact description thereof, reference bein g hadto the accompanying drawings, making part of this specification, and inwhich- Figure is a top view or plan, and Fig. 2 a sideelevation, of partof a heated-air engine containing my invention. Fig. 3 is a vertical andlongitudinal section, and Fig. 4L a vertical and transverse section, ofthe hot-air duct and vaporizing-trough, to be hereinafter explained.Fig. 5 is a lateral section of such pipe on line a b of Fig. 2.

Heretofore in the construction and operation of heated-air engines aformidable objection has been experienced in the burning out ordestruction of the induction and eduction valves, as well as other partsof the engine, from the intense heat required to drive it at highpressure. In running the engine at its highest power or pressure theheat must necessarily be increased to a great degree, consequentlyincreasing the consumption of fuel and tending to ultimately destroydicerent parts of it.

My invention has for its object to obtain the highest power of theengine (if not to greatly increase its power from that which can beobtained from the employment of heated air alone) without any increaseof heated air or consumption of fuel from that required to run it at alimited pressure or rate of power, or, in other words, to reduce thetemperature or keep it at a moderately-low point and at the same timeincrease the power or pressure of the heated air required to drive theengine, and, as a consequence, keep the valves, as well as the cylinderand other parts, comparatively cool and prevent their scaling or beingburned out and destroyed.

The invention consists in combining with the air-duct which leads from4the fire-box to the valve-chamber a vaporiZiug-trough for containingwater and converting it into vapor or steam by means of the hot air fromthe tire, which vapor or steam combines with the hot air and passes withit into the valve-chamber of the engine and increases its pressure orpower without increasing its temperature.

When little power is required of the. engine it will be desirable to usevery little if any vapor, as the heated air will be sufficient with amoderate amount of fire in the {ire-box. When more power is requiredwater may be admitted to the trough in sufficient quantities to effectthe desired result, varying in quantity with the required increase ofpower, as it will, of course, be understood that the more water admittedto the trough the greater the quantity of steam produced.

The quantity of water required will be very small, probably not toexceed at any time a column one-half a cubic inch in volume for afour-horsepower engine, and its rate of admission may be adj usted by aregulator attached to the engine and connected with the pump whichsupplies the water.

It is obvious that the amount of steam may be increased to any extent byincreasing the radiating or heating surface of the trough.

This vaporizing-trough may be made of castiron, pure copper, or carbon,such as is deposited in gas-retorts, or wrought-iron or steel, or eveniire-brick, may be-employed for this purpose, the object being to obtaina material which shall withstand the greatest amount of heat inconnection with the water or vapor. The upper surface of the trough maybe punctured with a number of small holes, inclining at an angle towardthe surface of the water, in order to direct jets of heat directlythereto.

I do not intend in this specification to conne myself to any particularform of Vaporizing-trough or mode of heating the water ad mit-ted aboutthe hot-air duct, the more important feature bein g its locationth atis, between the fire and the valve-chamber of the engine.

As shown in the accompanying drawings, it is a semicircular orpartially-cylindrical trough, a, placed within the hot-air duct b, andstands at an angle to the horizon of fortyve degrees,or thereabout, andhas a number of partitions, c c c, Ste., extended across it, asrepresented. The water, being admitted into the upper end of the trough,will flow over the successive partitions and be held partiallysuspended, as it were, in the current of hot air flowing from thefire-box. Before reaching the bottom of the trough the water will havebeen entirely converted into steam or Vapor, and, mixing with thehot-air current in its passage to the cylinder of the engine, willgreatlyincrease its pressure or power without increasing itstemperature.

When the engine is at rest no steam will be formed, because the water,being admitted in regular jets, is entirely varporized at each stroke ofthe engine. As soon, however, as the engine is started the current ofhotair, impinging against the trough, vaporizes the liquid injected intoit. The trough may be pointed at either or both ends to allow the air tomore readily pass around and in contact with its surface.

The air-duct above and below the Vaporizingtrough should be contractedso as to present about the same internal area as that portion of itwhich surrounds the trough.

The lire-box of the engine is represented at A, the cylinder at B, theforcing-pump at C, and the Valvebox at D, as they are constructed andarranged in the ordinary manner. Only their comparative locations andexternal forms are exhibited in the drawings.

If desirable, the exhaust air from the engine may be used to heat theWater previous to its introduction to the vaporizirigtrough.

Instead oi' the vaporizing-trough, as above described, for generatingVapor, I have contemplated the employment of a wire-gauze or perforateddiaphragm or shelf, to be placed within the air-duct.

I am aware thatin an English patent gran ted to Sir George Caley in theyear 1837 Water was introduced in jets upon the top of the fire toproduce steam for the purpose of starting the engine. It is evident thatthere are great objections to this, one being that the fire is soondeadened and put out, another that the ashes and dirt are raised inquantity from the lire and carried into the air-duct and Valvebox, whileby my mode of applying the Water the tendency is to allay any dust Whichmay escape into the hot-air duct.

Iam also aware that steam from a steam-boiler has been introduceddirectly into the valveboX, and from there passed into the cylinder, asshown in patent numbered 33,497, and dated October 15, 1861, andconsequently I lay no claim to such.

What I claim as my invention is- 1. A vessel or reservoir placed betweenthe furnace and the Working-cylinder, into which jets of water areintroduced at certain intervals and in regulated quantities, for thepurpose specified.

2. The combin ation ot' the vaporizin g-tro ugh,

or its equivalent, with the hot-air duct, essen- Y tially as above setforth.

3. The peculiar construction of the trough a, as made pyramidal orpointed at one or both I its ends, and With the partitions c c c,inmanner and to operate as before set forth and explained.

OYRUS W. BALDWIN.

Vitnesses:

F. C. RIcHARDs, EBEN B. FOSTER, Jr.

